Ultrasonic micro-moulding technology was used to process high performance polymer polyphenylsulfone (PPSU) due to investigate mechanical and chemical characteristics of manufacturing parts. Both the processing window and dependence between the main input parameters, in this case amplitude, plunger velocity and ultrasonic exposure time and their influence on the mechanical properties were appointed. The experiments showed that each available amplitude level (58 µm, 52.2 µm, 46.4 µm, 40.6 µm) are suitable to produce specimens characterised by high mechanical strength but only when combined with the appropriate values of the rest of the parameters. The parameter, which influenced the most on the part degradation is the ultrasonic vibration time. Samples from the combination of parameters, where the amplitude and velocity had the highest value but time of sonication is one of the lowest are less exposed for degradation. Cavitation bubbles makes polymer falling apart which decreases mechanical strength of the manufacturing parts. Degradation was observed via FTIR analysis even if it was not visually visible. Finally, the model as a tool for selecting the appropriate values for the input process parameters when using the novel ultrasonic micro-moulding technology required to produce PPSU parts characterised by their high mechanical strength was developed.

The effects of human recombinant interleukin-4 (rIL-4) on metastatic melanoma (lymph node)-derived T lymphocytes cultured with human recombinant interleukin-2 (rIL-2) were studied. Lymphocytes isolated from melanoma-invaded lymph nodes were cultured in media with rIL-2 in the presence (MB-2,4) or absence (MB-2) or rIL-4 for up to 48 days. A majority of lymphocytes grown in both cultures were CD3+ T lymphocytes. Addition of rIL-4 to the rIL-2 culture abrogated the growth of the CD3-, CD56+ cell population [natural killer (NK) cell], which were present in culture with rIL-2 alone. Lymph-node-derived T lymphocytes that had expanded under MB-2,4 conditions lysed only autologous melanoma cells and they maintained the autologous-specific cytolytic activity during the entire culture period. They did not lyse K562, Daudi, or allogeneic target cells. Monoclonal antibodies (MAbs) against CD3 molecules and MHC class I molecules but not MHC class II molecules inhibited the specific lytic functions of T lymphocytes under MB-2,4 culture conditions. Collectively, these data indicate that in lymphocyte culture derived from melanoma-invaded lymph nodes, rIL-4 inhibits the rIL-2-dependent proliferation of NK cells and antigen nonspecific killer T lymphocytes and also effectively abrogates the rIL-2-induced NK and lymphokine-activated killer (LAK) activities.

Taxpayers establishing their economic and personal interests in more than one country run the risk of becoming a tax resident in more than one tax jurisdiction. The problem of possible double residency shall be solved by Article 4(2) and (3) (the so-called Tie-Breaker Rule) of the OECD Model Tax Convention. Both articles are falling back on national legal definitions, which raises the risk of their different interpretation by the participating countries. The aim of the study is to demonstrate the differences in interpretation of such terms as "resident", "permanent home", "centre of vital interests" and "habitual abode" in Poland and Germany. The authors also try to find out whether and how the consistency of the decision-making process can possibly be achieved. The analysis shows that it can be supported by the efficient and effective information exchange processes as well as increased international cooperation between the tax administrations and the administrative courts. As a research tool the authors used an analysis of subject-matter literature, legal acts, and court decisions.

One of the effects of globalization is the intensification of tax avoidance which leads to the erosion of tax bases in many tax jurisdictions. Not surprisingly, one of the main objectives of governmental policies is to tighten (seal) their tax systems. This can be illustrated by the changes to the tax procedures and powers of tax authorities introduced in Poland. The aim of the article is to examine to what extent these changes have impacted the tax gap. The author analyzed the relevant literature, legal provisions and empirical data. The results demonstrate that the changes in question deserve approval and they could impact the tax gap. However, they do not fully solve the problems resulting from the former legal solutions and it is not entirely clear whether the higher revenues to the state budget result from the activities of tax authorities or whether they are primarily driven by economic growth and the growth in prosperity. The constantly growing gap in foreign CIT also calls for further action.

This paper aims to present the size and structure of passive income payments, such as dividends, interest, royalty payments, and fees for intangible services, made by companies domiciled in Poland belonging to a multinational enterprises (MNE) group. The authors formulate a hypothesis that tax jurisdictions offering extensive legal and tax incentives for holding structures, in particular concerning the tax treatment of dividends and other withholding tax payments, are the preferred location of holding companies. A review of the literature and legal sources precedes empirical research. The empirical analysis shows that passive income flows, including dividends, interest, royalties, and fees for intangible services, which constitute the dominant type of payments to holding companies, are directed from Poland primarily to countries with tax and regulatory solutions that are friendly to holding companies, including in particular the so-called intra-EU tax havens, namely Luxembourg, Cyprus, the Netherlands, Malta and Ireland. Real trade with these countries is neither significant nor proportional to the scale of passive income.